The recent issue with the Joker was atypical in that it was written mostly in text with artwork. That is to say, it was written like a short story, prose with pictures in the background, rather than showing the action panel-by-panel.
That said: the plot has the Joker's former henchmen being killed off in droves, and Batman trying to solve the case, naturally, checking out the Joker first of all. He appears in Arkham to be a mute, in a wheelchair, with his face covered in bandages. His speech therapist's name, as it turns out, is Miss Misakedjak, which Batman (naturally) immediately identifies as the Cree Trickster God: Harley Quinn.
Next murder scene, Batman figures it all out after noticing that the locations and appearance of the murders follow a pattern: "Snake scales, red and black. Blood on the tuxedo. Red Hook and Black Brothers and the Red House." He does at last find Harley, and tries to explain to her that the Joker's personality is changing again "You know how he changes every few years. You wrote the book, Dr. Quinzel. He has no real personality, remember, only a series or 'superpersonas.'". Naturally, she doesn't listen and escapes, heading to Arkham where the alarms are now going off.
In between scenes, we'd been treated to a look at the Joker's internal monologue.. entertaining stuff:
He's scrolling through a list of things that make him laugh. Blind Babies. Landmines. AIDS. Beloved pets in bad road accidents. Statistics. Pencilcases. BRUNCH! The periodic table of elements....Geniuses suffering irreversible brain damage. REAL bad news. Shattered faith. Sombreros. Politics. Fish being gutted. Fish being gutted. Fish being gutted.
Like a grub growing all wrong in a tiled cocoon, like a caterpillar liquefying to filth in its own nightmares or a fetus dissolving in sewage and sour milk, the Joker dreams, awake. His is the mal ojo, the evil eye. He wills Death upon the world.
Bowel Cancer. Fish being gutted. Mister Ed. Guns in schools. Cripples. Racism.
Breathing slowly in his bright and boundless hell, the Clown Prince of Cruelty dreams a new face, a new world, a Year Zero. An unforgettable golden age of comedy and crime!
Alzheimer's
The mosquito, meanwhile, gets the message, shudders and falls from the Joker's hand. Blind and crippled it spins in circles on the radiant floor, choking on tainted blood.
Batman.
He watches the tiny lofe go out, listens to the fading whine as it slowly curls up, like a hand becoming a fist, and dies.
Batman.
Eager to be born, he counts backward to midnight.
Anyway, long story short, the Joker makes his escape and Harley arrives with Batman in tow. It's now that we finally discover the whole of the Joker's plan. All the dead henchmen were killed to sever his links with the past. To unveil the new Joker, the ultimate sacrifice is to be made: having led Batman to Arkham, Harley is completely unaware that the sacrifice isn't the Dark Knight, but her. Batman reveals this just in time to save Harley, and the Joker rants as he and Batman fight. Highlights include "Both of us trying to find meaning in a meaningless world! Why be a disfigured outcast when I can be a notorious Crime God? Why be an orphaned boy when you can be a superhero?" and "I could never kill you...Where would the act be without my straight man?". The confrontation is brought to a sudden conclusion when a bullet rips through the Joker's shoulder with the words "You gotta stop ignoring me, Mistah Jay... Don'tcha love me no more?".
Oh, and while we can't really say for certain yet, everything seems to point to a yes on the Damian is Batman's son angle.